Due to the increasing scarcity of oil and its higher prices in North America, there has been a renewed interest in the burning of firewood and, as a result, there have been numerous proposals for devices for splitting firewood other than by a hand axe.
Conventionally, wood splitting devices include some form of frame which mounts at one end a hydraulic ram and pusher plate which, when actuated, drives a block of firewood into a splitting wedge or axe head arrangement at the other end of the frame. These devices normally have a small gasoline or similarily powered apparatus for driving the hydraulic pump with about 5 to 8 horsepower.
One of the problems with conventional machines is that, in a more simple single head wedges, a wood block has to be split twice to obtain quarter blocks. Four way knives have also been developed providing one vertical and one horizontal knife at right angles to the vertical knife but this arrangement requires extremely high horsepower. Moreover, after the vertical split is made the two halves of the block tend to slide off the horizontal knives without accomplishing the horizontal split. Moreover, horizontal knives in conventional machines normally force the bottom half of each side block downwardly where some form of interference with the main beam is usually experienced. This jams the machine to the point where stalling occurs, leaving the operator with a wood block that must be removed with a sledge hammer or similar device.